The recent advent of GW astronomy offers a new avenue to test gravity in the relativistic regime. The majority of GWs observed by LIGO and Virgo thus far were generated by the coalescence of BBHs; several tests of GR have already been conducted using these observations [1]}, [2]}, [3]}, [4]}. However, Hawking famously showed that stationary BHs in JFBD theory must have a trivial scalar profile, and thus are indistinguishable from the analogous solutions in GR [5]}. Although there are some possible scenarios that evade this no-hair theorem (see, e.g., Ref. [6]}), binary systems composed of BHs are generally expected to behave identically in JFBD theory and GR, and thus GWs from such systems are unable to constrain this scalar-tensor theory.
